1. Field of the Invention
The present invention relates to characterization of a silicon-on-insulator (SOI) wafer and, more particularly, to determining one or more functional parameters of the SOI wafer.
2. Description of Related Art
A growing number of semiconductor wafers in use today are silicon-on-insulator (SOI) wafers. Presently, semiconductor wafers have a relatively large diameter, e.g., 300 millimeters, and, prior to forming integrated circuits thereon, are relatively expensive to produce and/or acquire. Heretofore, characterization of a group of related semiconductor wafers, i.e., wafers formed from the same ingot, involved the physical formation of test structures on one or more test wafers selected from the group and the subsequent testing of the selected test wafer(s).
Once test structures are physically formed on a test wafer, the test wafer becomes unsuitable for use as a production wafer. Hence, once utilized, a test wafer is often discarded with the subsequent loss of revenue the wafer may have generated had it been utilized as a production wafer along with the cost associated with the production and/or acquisition of the wafer itself.
Because of the increasing use of SOI wafers, there is a growing and, heretofore, unfulfilled need for testing SOI product wafers in a non-destructive and non-contaminating manner.